1. Field of the Invention
The invention relates to a connecting device, such as a swivel hook made of a synthetic resin, which can be easily connected to a stopper attached to a bag such as a shoulder bag or a knapsack by hooking or a buckle made of a synthetic resin for use in connecting or disconnecting both ends of a single belt or two belts, and more particularly, to a connecting device in which a belt attaching member and a connecting device main body are rotatable with respect to each other.
2. Description of Related Art
Conventionally, a swivel hook which is one of connecting devices, in which a hook-like swivel hook main body and a belt attaching member are connected rotatably to each other, have been put to practical use as disclosed in, for example, Japanese Utility Model Application Publication (JP-Y) No. 62-27701 and U.S. Pat. No. 6,286,190.
The swivel hook of JP-Y-62-27701 has a swivel hook main body and a belt attaching member. The swivel hook main body comprises a neck portion and an engagement head which is provided at a front end of the neck portion and expanded in an outward direction from a center of an axis line such that a diameter of the engagement head can be reduced. The belt attaching member has a through hole in which the neck portion and the engagement head can be inserted. The through hole has a small-diameter hole portion having a smaller diameter than the diameter of the engagement head and a large-diameter hole portion having a larger diameter than the diameter of the engagement head connected to the small-diameter hole portion via a stepped portion. When the engagement head of the swivel hook main body is inserted from the small-diameter hole portion of the through hole and engaged with the stepped portion, the swivel hook main body and the belt attaching member can be easily assembled.
The swivel hook disclosed in U.S. Pat. No. 6,286,190 has a swivel hook main body and a belt attaching member. The swivel hook main body comprises a neck portion and an engagement head which is provided at a front end of the neck portion and expanded in an outward direction from a center of an axis line. The engagement head is made to pass through a through hole in the belt attaching member and exposed on an outer face of the through hole. Then, a ring-like opening member made of elastic material such as rubber is interposed between the engagement head and the belt attaching member so as to assemble the swivel hook. The opening member absorbs an impact when the swivel hook main body is pulled, and when an excessive shock is received, the swivel hook main body slips out of the belt attaching member.
This kind of the swivel hook is demanded to be assembled securely and easily because the swivel hook main body and the belt attaching member are manufactured separately. Further, it is demanded not to produce a frictional sound between the swivel hook main body and the belt attaching member.
The swivel hook disclosed in JP-Y-62-27701 can be assembled easily only by inserting the engagement head of the swivel hook main body into the through hole in the belt attaching member, the through hole comprising the small-diameter hole portion and the large-diameter hole portion. The engagement head has a structure which can be expanded or reduced in a diameter direction. The engagement head is inserted from the small-diameter hole portion with the diameter of the engagement head reduced and then its diameter is expanded at the large-diameter hole portion so that the engagement head is engaged with the stepped portion and accommodated in the large-diameter hole portion. Therefore, the engagement head is accommodated inside the through hole and thus, is not exposed outside, thereby presenting a good appearance. However, it is necessary to select a material suitable for the swivel hook main body and the belt attaching member in consideration of the strength and friction. In many cases, a frictional sound offensive to the ear is generated upon a rotation, depending on the material adopted.
The swivel hook disclosed in U.S. Pat. No. 6,286,190 comprises three composition members, that is, a swivel hook main body, a belt attaching member and a ring-like opening member which is interposed between the swivel hook main body and the belt attaching member. The swivel hook main body and the belt attaching member are made of metal, and the ring-like opening member is made of a synthetic resin having elasticity such as rubber. However, it is troublesome to assemble the three components because no large-diameter hole portion is formed unlike JP-Y-62-27701, and the engagement head is exposed outside, thereby not presenting a good appearance. Although the ring-like opening member is disposed mainly to absorb a shock, it is difficult to eliminate the frictional sound offensive to the ear generated between the metal and the elastic material such as rubber when the metallic swivel hook main body is rotated with respect to the belt attaching member unless any special processing is executed.